The present invention relates to a connecting mechanism for electronic circuit board blanks, and more particularly to a connecting mechanism including a succession of electronic circuit board blanks for supporting electronic parts thereon and joined at spaced intervals by narrow joints, which can subsequently be cut off automatically to separate the electronic circuit board blanks from each other without causing damage to the electronic parts so that electronic circuit boards can be produced from a board material with a high yield.
Small electronic circuit boards have been in wide use which make electronic products small in size, allow them to be produced highly efficiently, and permit electronic components mounted thereon to be electronically connected to each other for ensuring accurate operation of the products. For example, slender electronic clinical thermometers incorporate narrow circuit boards on which small electronic parts are mounted.
For mass-producing circuit boards to be assembled in electronic clinical thermometers, a plurality of board blanks each with a printed circuit are contoured in a relatively large insulative strip. After various electronic parts such as one-chip microcomputers, resistors, and the like are mounted on the board blanks, the board blanks are cut off for use as electronic circuit boards. The board blanks on the strip are joined together by joints which have perforations for easy separation.
The board blanks are separated or cut off from the skeleton after the electronic parts have been mounted thereon, as described above. The board blanks as they remain joined to the strip are closely positioned at distance which approximate the diameter of the perforations. Therefore, it is quite difficult to sever the board blanks off the strip with a press or the like. Since the perforations extend entirely around the board blanks, if the board blanks were cut off by an automatic machine, the board blanks and the mounted electronic components would be subjected to stresses applied by the cutting forces, tending to damage the circuits and the electronic components. Accordingly, it is the current practice to separate the board blanks manually along the perforated cutoff lines. The process of separating the board blanks is quite time-consuming, and hence the mass production of such electronic circuit boards is low in efficiency.